Analysis of hepatitis C virus isolates among healthy blood donors and drug addicts in Chiang Mai, Thailand

Abstract

Hepatitis C virus (HCV) isolates obtained from 25 anti-HCV antibody-positive healthy blood donors and 29 drug addicts in Chiang Mai, Thailand, were analyzed. HCV RNA was detected in 23 blood donor samples (92%) and 24 drug addict blood samples (83%) by PCR for a portion of the NS5 region. Subtype analysis revealed that HCV type 3a (HCV-3a) was the prevailing subtype (30%), which was followed in prevalence by HCV-la (21%),-lb (13%),-3b (13%), and-6a (2%). Six (13%) of the 47 isolates showed low sequence similarities with known types and subtypes. The sequence variants could be grouped into four branches in a molecular evolutionary phylogenetic tree.

Hepatitis C virus genotype distribution in China: Predominance of closely related subtype 1b isolates and existence of new genotype 6 variants

“…The predominance of HCV genotype 3 is consistent with a recent report that it accounted for 56% and genotype 1 accounted for 13% of the HCV isolates from this area [Chen et al, 2002b]. Genotype 3 is the most prevalent genotype in countries neighboring the Kunming area such as Bangladesh [Ohno et al, 1997], Burma , and Thailand [Apichartpiyakul et al, 1994;Greene et al, 1995;Mellor et al, 1995;Doi et al, 1996;Chinchai et al, 2003]. The genotype 6 variants were previously designated genotypes 7, 8, 9, and 11 [Tokita et al, 19947, 8, 9, and 11 [Tokita et al, , 19957, 8, 9, and 11 [Tokita et al, , 1998], but phylogenetically should be grouped under the major genotype 6 .…”

“…The two dashed circles identify the sequences in groups A and B. Mellor et al, 1995Mellor et al, , 1996Zhang et al, 1995;Adams et al, 1997;Ohno et al, 1997;Chan et al, 1998;Wong et al, 1998], Macau [Davidson et al, 1995;Wang et al, 1995], Thailand [Apichartpiyakul et al, 1994;Theamboonlers et al, 2002;Chinchai et al, 2003], and Vietnam [Tokita et al, 1994[Tokita et al, , 1998Stuyver et al, 1995]. In Hong Kong, 6a was found in approximately 30% of HCV infected blood donors [McOmish et al, 1994] and about 60% HCV infected IVDAs where it appears to have spread through intravenous drug use [Wong et al, 1998].…”

“…The genotype 6 variants were previously designated genotypes 7, 8, 9, and 11 [Tokita et al, 19947, 8, 9, and 11 [Tokita et al, , 19957, 8, 9, and 11 [Tokita et al, , 1998], but phylogenetically should be grouped under the major genotype 6 . Previously, they were identified only in Indonesia [Tokita et al, 1998] and a contiguous region in Vietnam (Hanoi and Ho Chi Minh) [Tokita et al, 1994;Stuyver et al, 1995] and Thailand (Chiang Mai and Bangkok) [Apichartpiyakul et al, 1994;Mellor et al, 1995;Tokita et al, 1995Tokita et al, , 1998Doi et al, 1996;Simmonds et al, 1996], and a single case in Burma . The latter three countries are close to the Kunming area and within the last decade the Kunming area has become a significant center for trafficking drugs into China and other Asian countries [Beyrer et al, 2000].…”

Frequent Detection of Hepatitis C Virus Subtype 3a (HCV‐3a) Isolates in Thailand by PCR Using Subtype‐Specific Primers

“…The serum samples were tested for anti-HCV antibodies by second generation ELISA kits (Abbott Diagnostics, Wiesbaden-Delkenheim, Germany; Ortho Diagnostic, Tokyo). RNA was extracted from anti-HCV antibody-positive sera and reverse-transcribed into cDNA using HCV-specific primer #186 (14) as described previously (1,(5)(6)(7)(8). The resultant cDNA was amplified by nested PCR: The first round PCR was performed over 35 cycles each consisting of 1 min at 94 C, 1.5 min at 55 C and 2 min at 72 C with consensus primers #186 and HC3 (6, 7) and 'Tth' DNA polymerase (Toyobo, Osaka, Japan).…”

Hepatitis C Virus Infection‐Associated Markers in Sera from Blood Donors in Surabaya, Indonesia

“…To detect HCV viremia, RT-PCR was performed with anti-HCV-positive sera. Briefly, a portion of the NS5B region and/or a portion of the 5'-untranslated region (5 UTR) of the viral genome were amplified as described previously (2,6,7,13,14), electrophoresed in 2%agarose gel containing ethidium bromide, and visualized by UV illumination. RNA and IgM anti-HCV.…”